Testing javascript code for crossbrowser issues

In my web applications I need to test my javascript code for crossbrowser issues. Some clients are complaining about javascript errors. The most probably reason is different browsers they use because it's hard to reproduce on the developer machines. Are there tools that do automated testing and repo开发者_JS百科rt issues for javascript?

You can try TestSwarm Haven't used it myself, though, so don't have much to say about its quality and effectiveness.